The foam plastic material referred to above is normally a foam polymer, such as polypropylene, polyethylene, polystyrene and copolymers thereof.
A container of this sort is known, for example, from PCT Patent Application No. WO-A-2012028567.
Collapsible containers molded from foam plastic are known, which can be folded from an erect work configuration to a relatively highly compact, relatively space-saving, flat configuration for transport or storage when not in use. Accordingly, collapsible containers of this sort are normally parallelepiped-shaped, and comprise a bottom wall, and four lateral walls hinged to the bottom wall so as to fold inwards or outwards of the container, onto the bottom wall or into a position coplanar with the bottom wall, and so flatten the container.
Containers of this sort are usually molded in the form of a blank (i.e., a flat, contoured sheet with thinner areas connecting the lateral walls to the bottom wall, and which act as hinges by which to rotate the lateral walls with respect to the bottom wall). The container is therefore produced in the flat configuration and folded into the erect configuration for use. The walls of the container normally have appendages which fit together and act as fasteners in the erect configuration, to achieve a rigid, but at the same time easily collapsible, container.
Though relatively simple, and for this reason relatively widely used, the above production method has the major drawback of the blank—especially when producing relatively very large containers—requiring a relatively extremely large, and therefore bulky, relatively difficult to handle, mold.